Error installing smbus2 on pocketbeagle

[Marius Strom]

I am trying to install smbus2-0.2.1 on a Pocketbeagle running Debian v9.5.  While I do not have an internet connection, I've utilized WinSCP to get the appropriate wheels and tar files over to the beagle to install pip v18.1 and setuptools v40.6.3.  However, upon trying to install smbus2-0.2.1, I get the following error:

debian@beaglebone:/var/lib/cloud9$ pip install smbus2-0.2.1.tar
Processing ./smbus2-0.2.1.tar
    Complete output from command python setup.py egg_info:
    error in smbus2 setup command: 'extras_require' must be a dictionary whose values are strings or lists of strings containing valid project/version requirement specifiers.
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-req-build-f0O3p9/

Per a previous bug report (https://github.com/kplindegaard/smbus2/issues/21), I tried untarring smbus2-0.2.1 and commenting out the "extras_require" lines.  Upon running setup.py, I got the following:

debian@beaglebone:/var/lib/cloud9/smbus2-0.2.1$ python setup.py
Traceback (most recent call last):
  File "setup.py", line 63, in <module>
    "Programming Language :: Python :: 3.6"
  File "/usr/lib/python2.7/distutils/core.py", line 111, in setup
    _setup_distribution = dist = klass(attrs)
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/setuptools/dist.py", line 225, in __init__
    _Distribution.__init__(self,attrs)
  File "/usr/lib/python2.7/distutils/dist.py", line 287, in __init__
    self.finalize_options()
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/setuptools/dist.py", line 257, in finalize_options
    ep.require(installer=self.fetch_build_egg)
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/pkg_resources.py", line 2072, in require
    working_set.resolve(self.dist.requires(self.extras),env,installer))
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/pkg_resources.py", line 2282, in requires
    dm = self._dep_map
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/pkg_resources.py", line 2511, in _dep_map
    self.__dep_map = self._compute_dependencies()
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/pkg_resources.py", line 2544, in _compute_dependencies
    common = frozenset(reqs_for_extra(None))
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/pkg_resources.py", line 2541, in reqs_for_extra
    if req.marker_fn(override={'extra':extra}):
  File "/usr/local/lib/python2.7/dist-packages/distribute-0.6.45-py2.7.egg/_markerlib/markers.py", line 109, in marker_fn
    return eval(compiled_marker, environment)
  File "<environment marker>", line 1, in <module>
NameError: name 'sys_platform' is not defined

I'm not sure where to go at this point.  Previous solutions were based on upgrading the version of setuptools that was available, but I have the most up-to-date version, so that's out.  Any thoughts?